“Digital assets have value, sometimes sentimental, and sometimes commercial, just like a boxful of jewelry,” said John M. Riccione, a lawyer at Aronberg Goldgehn Davis & Garmisa in Chicago. “There can be painful legal and emotional issues for relatives unless you decide how to handle your electronic possessions in your estate planning.”

Many services and programs have sprung up to help people prepare for what happens after their last login.

Google has a program called Inactive Account Manager, introduced in April, that lets those who use Google services decide exactly how they want to deal with the data they’ve stored online with the company — from Gmail and Picasa photo albums to publicly shared data like YouTube videos and blogs.

The process is straightforward. First go to google.com/settings/account. Then look for “account management” and then “control what happens to your account when you stop using Google.” Click on “Learn more and go to setup.” Then let Google know the people you want to be notified when the company deactivates the account; you’re allowed up to 10 names. You choose when you want Google to end your account — for example, after three, six or nine months of electronic silence (or even 12 months, if you’ve decided to take a yearlong trip down the Amazon).

Google has ways to make sure that your electronic pulse has really gone silent; it checks for traces of your online self, for example, by way of Android check-ins, Gmail activity and Web history. Then, a month before it pulls the plug, Google alerts you by text and e-mail, just in case you’re still there. If silence has indeed fallen, Google notifies your beneficiaries and provides links they can follow to download the photographs, videos, documents or other data left to them, said Nadja Blagojevic, a Google manager.

And if you just want to say goodbye to everything, with no bequests, you can instruct Google to delete all of the information in your account.

Naomi R. Cahn, a professor of law at George Washington University Law School in Washington, says Google’s new program is a step forward in digital estate planning. “People should carefully consider the fate of their online presences once they are no longer able to manage them,” she said.

Other companies may also be of help in planning your digital legacy. Many services offer online safe deposit boxes, for example, where you can stow away the passwords to e-mail accounts and other data. Accounts like this at SecureSafe, are free for up to 50 passwords, 10 megabytes of storage and one beneficiary, said Andreas Jacob, a co-founder. Accounts can be accessed from a browser, or from free iPhone, iPad and Android apps. The company also offers premium services for those who need a larger storage space, more passwords or more beneficiaries.

There is always your sock drawer or another physical repository to store a list of your user ID’s, should you be deterred from online lockboxes by fear of cyberattacks or the risk that computer servers that may not be there in a few decades, said Alexandra Gerson, a lawyer at Helsell Fetterman in Seattle.

“Make a private list of all your user names and passwords for all the accounts in which you have a digital presence, and make sure you update the list if you change login information” Ms. Gerson said. “Don’t put user names and passwords in your will, though, as it becomes a public record when you die.”

Make sure that your executor or personal representative understands the importance of preserving these digital assets, and knows how to find them, said Laura Hoexter, a lawyer at Helsell who also works on inheritance issues. “Preferably the person should be tech-savvy,” she said, and know about your online game accounts, your PayPal account, your online presence on photo storage sites, social media accounts and blogs, and even your online shopping accounts where your credit card information is stored so that the information can be deleted.

AFTER you die, an executor or agent can contact Facebook and other social media sites, establish his or her authority to administer the estate, and request the contents of the account.

“Most accounts won’t give you the user name and password, but they will release the contents of the account such as photographs and posts” to an executor, Ms. Hoexter said.

Transfer at death can depend on the company’s terms of service, copyright law and whether the file is encrypted in ways that limit the ability to freely copy and transfer it. Rights to digital contents bought on Google Play, for example, end upon the person’s death. “There is currently no way of assigning them to others after the user’s death,” Ms. Blagojevic said.

Encryption is a common constraint, but there are exceptions. Apple’s iTunes store, for example, has long removed its anti-copying restrictions on the songs sold there, and Ms. Gerson advises people to take advantage of this in their digital planning. “Get your music backed up on your computer,” she said.

Up to five computers can be authorized to play purchases made with one iTunes account, and a company support representative advises that users make sure that their heirs have access. At Kindle, too, family members with user ID information for the account can access the digital content.

Professor Cahn in Washington says the time to prepare for the digital hereafter is now, particularly if serious illness is a factor. “If someone is terminally ill,” she said, “in addition to getting emotional and financial issues in order, you need to get your Internet house in order.”

E-mail: novelties@nytimes.com.

A version of this article appears in print on , on Page BU3 of the New York edition with the headline: Bequeathing the Keys To Your Digital Afterlife. Order Reprints | Today’s Paper | Subscribe